Albert p



(No Model.) A. P. MASSEY. v

AUTOMATIC VALVE FOR AIR BRAKES.

UNITED STATES PATENT OFFICE.

' ALBERT P. MAssEY, 0F WATERTOWN, NEW YORK, ASSIGNOR TO THE EAMES VACUUM BRAKE COMPANY.

AUTOMATIC VALVE FOR AIR-BRAKES.

SPECIFICATION forming part of Letters Patent No. 447,337, dated March 3, 1891.

Application filed July 10, 1890. Serial No. 358,298. (No model.)

To all whom it may concern:

Be it known that I, ALBERT P. MASSEY, of Watertown, in the county of J eflferson and State of New York, have invented an Improved Automatic Valve for Air-Brakes, of which the following is a specification, reference being had to the accompanying drawings, in which Figure 1 is a section on line 1 1 of Fig. 2, and Fig. 2 is an end view with parts removed and other parts shown in section on line 2 2 of Fig. 1, of one form of my valve. Figs. 3 and 4 are details described below.

In air-brakes as long used the air-reservoir and brake-cylinder are connected to a pipe (leading along the train from the engineers valve and commonly called the train pipe) by means of a contrivance commonly called a triple valve, so constructed that a reduction of pressure in the train pipe operates the triple valve in one direction, thereby applying the brakes by increasing the air-pressure in the brake-cylinder, while an increase of pressure in the train-pipe operates the triple valve in'the other direction, thereby opening the brake-cylinder to the atmosphere and letting off the brakes and also opening a passage from the train-pipe to the auxiliary reservoir, so as to recharge it with compressed air. A variety of these contrivances known as triple valves. are well known, and my invention relates to contrivances of this class; and it consists, first, in a novel combination of a piston or valve operated by difference of pressures on its opposite sides with two valves which it operates in a peculiar manner, all more fully described below, and, secondly, in the combination of a piston or valve operated by difference of pressures on opposite sides with a piston and a valve controlled by it, which valve controls a passage from the trainpipe to the brake-cylinder, as more fully described below.

In the drawings, A is a passage to the trainpipe, 13 a passage to the auxiliary reservoir, and O a passage to the brake-cylinder. For

convenience the casing b is made in three parts, as shown, and a casting (not shown) covers the passages B and C and has passages through it which are continuations of ber4 and passes by piston D by means of passage 5 into chamber 6, and from chamber 6 through passage B, until the pressure is equalized on both sides of piston Dthat is, the pressure in the auxiliary reservoir and chamber 6, which are connected by passage B, is substantially the same as that in the train-pipe and chamber 4 connected by passages 3. The passage 7, by which the auxiliary reservoir is connected to the brake cyl inderthat is, passage 13 connected with passage O-is controlled by the valve F, and the passage 8', by which the brake-cylinder is connected to the atmospherethat is, the exhaust from passage Cis controlled by the valve G. These three valves D, F, andGact automatically as follows: When in the position shown, the air-pressure is equal in the train-pipe, chambers 4 and 6, and the auxiliary reservoir. The brake-cylinder is open to the atmosphere with the brakes off and the train moving. It'- the brakes are to be applied so as to slow up the train, the engineer reduces the pressure in the train-pipe slightly, (in a manner too well understood to require description.) thereby making the pressure in chamber 4 slightly less than that in chamber 6, and piston D is at once moved from right to left, carrying with it valvesFand G. This motion of valve G closes the exhaust 8 from passage 0, and this motion of valve F connects passages B and Othat is, the reservoir and brake-cylinderand compressed air flows from chamber 6 and the reservoir through passage 7 into the brake-cylinder, applying the brakes with slight force, for passage 7 past valve F is small; but as soon as the expansion of the compressed airin cham- Too her 6 and the reservoir has reduced the pressure on the right of piston D slightly below the pressure on its left, piston D is moved to the right until it forces valve F on its seat, thereby cutting off chamber 6 and the reservoir from passage 7. This motion of piston D is not enough'to move valve G nor to uncover passage 5, so that the brakes remain applied with slight pressure. If it becomes necessary to apply the brakes more forcibly, the engineer again reduces slightly the pressure in the train-pipe with the same result as before, except that the valve G is not moved, and so for a further reduction of pressure in the train-pipe until the brakes are gradually applied with force enough to bring the train to a stop. To start the train the engineer increases the pressure in the train-pipe, (in a manner too well understood to require description,) thereby moving piston D to the position shown in Fig. 1, and this full forward stroke of piston D not only forces valve F more firmly on its seat, (by compressing spring j,) but also shifts valve G back to its position, as shown in Fig. 1, thereby opening passage 0 to the atmosphere and allowing compressed air to escape from the brake-cyL inder through passages C and exhaustpassage 8.

My invention as embodied in the contrivance just described is the combination of the three valves D,.F, and G with the passages A, B, and Ca passage connecting A and B controlled by valve D, a passage connecting B and C controlled by valve F, and an exhaust-passage from passage C controlled by valve G; and while I am aware that other triple valves are known, yet so far as I have any reason to believe I am the first to use the two valves F and G, both controlled by the valve D, the valve F controlling the passage which connects the passages 13 and C, and the valve G controlling only the exhaust from the passage C, for heretofore in all triple valves known to me the valve which most nearly resembles my valve G controlled not only the exhaust from passage 0, but also controlled a passage connecting B and 0, and required to be moved whenever the Valve D moved; but in my contrivance the valve G is moved only at the first stroke of valve D from right to left, and at the last stroke of valve D from left to right and remains stationary during the intermediate motions of valve D, thereby making valve D far more sensitive than in any other contrivance of this kind known to me. Moreover, the full function of valve F is simply to connect and disconnect passages B and C, and this also is anovel feature, and it is owing to this that I am enabled to keep valve G at rest while valve D is acting merely as a piston.

It will be obvious that the valves F and G must have a motion not only with but relative to the stem d ofpiston D, and I have shown convenient devices for those purposes, which will be plain from Fig. 1; but these details of construction are obviously capable of large variation, the gist of thematter beinga valve which controls a passage from B to C, and a second valve which controls the exhaust from C, but these valves being controlled by I), which not only controls their valves, but also controls a passage from A to B.

The second feature of my invention relates to the sudden application of the brakes on an emergency, and this I do by means of the valve H, which is acted upon on one side by the train-pipe pressure aided by the spring 7L and on the other side by the pressure in cham her 6, so that an y sudden and large decrease of pressure in the train-pipe will cause the pressure in the chamber (3 to move valve I-I against spring h, and thereby uncover passage 9. The compressed air in the train-pipe will then act through passaget) upon piston J and move it in cylinder j, so as to open valve K, when the compressed air in the trainpipe will lift check-valve 7: and escape past valves 7; and K into the brake cylinder. Moreover, this sudden large decrease of pressure in the train-pipe will also operate piston D, closing valve G and opening valve F, as before described.

The main purpose of opening valve K,which controls a passage connecting the train-pipe with the brake-cylinder, is to aid in the sudden and large reduction of pressure in the trainpipe, for in a long train the brakes will not be applied to the rear cars speedily and with full power unless there be some escape of air provided from the train-pipe other than the escape through the engineers valve but with a passage at each car fromthe train-pipe to the brake-cylinder for use in an emergency the sudden application of the brakes at the first car reduces the pressure in the train-pipe almost instantly, and that reduction applies the brakes to the next car, and so on, as will be well understood by all skilled in the art without detailed description, for I am aware that I am not the first to provide a passage from the train-pipe to the brake-cylinder; but so far as I have any reason to believe I am the first to do this by means of an automatic valve, which sets in operation a second valve controlling a passage from the train-pipe to the brake-cylinder.

The checkvalve k is not essential, but serves a useful purpose in governing the pressure in the brake-cylinder after the pressure in the train-pipe becomes less than that in the brake-cylinder, which is particularly desirable in case of an accidental rupture of the train-pipe.

The seat h of the valve II is shaped as clearly shown in Figs. 8 and 4, which are essential details illustrating the proposed construction of the valve II and its seat. The seat 71, is of course secured to casing b.

Vhat I claim as my invention is- In a triple valve, the main-valve piston having one side open to pressure from the auxiliary reservoir and the other side open to train-pipe pressure, combined with a valve In testimony whereof I have signed my name controlling a direct passage from the trainto this specification, in the presence of two 10 pipe to the brake-cylinder, a piston actuating subscribing witnesses, on this 8th day of July, said valve, 'a passage leading from the train- A. D. 1890.

pipe to said piston, and a valve controlling said passage and subject on one side to auxiliary-reservoir pressure and on the other to train-pipe pressure.

ALBERT P. MASSEY.

\Vitnesses: I

H. D. MORGAN, MICHAEL J. lWIoRKIN. 

